Motion profile generator.

[richard]

my basic premise is that the input to the pid filter is velocity error (not position error) . the required velocity (setpoint) is found from a lookup tables who's in put is based on position . The move routine has 5 possible modes 4 is start a new move , 3 accelerate ,2 steady speed (cruise) ,1 decelerate, 0 in position , -1 stalled (failure).
The lookup table was developed by - getting motor running at various velocities and throwing the brakes on (l393d style) and measuring the number of ticks travelled till at rest ,
I plotted these in a spread sheet (the motor I'm using is a 171:1 gear motor 564 ticks per rev, target vel is 32 rpm ) interestingly the pos vs vel curve is ver nearly parabolic.
the clever bit is using two lookup tables "the multi_map function" to interpolate the best velocity for the current position using only 9 entries in each table